Sigmafine Global Factors
When you create a database, an Element is automatically created that stores the common global factors for the Sigmafine analysis and computation. This Element is called SF_GlobalFactors and is of Element type \<None>. The values of the global factors depend on the library you use to create the database. The Sigmafine library uses the U. S. settings. The ‘SigmafineSI’ library uses the international settings.
Figure 212 shows the position of the SF_GlobalFactors Element in the System Explorer tree.
This section of the appendix defines the Attributes used in the global factors Element and outlines how to change these factors from the defaults. The SF_GlobalFactors Element does not need to be included in the Model collection of elements for the factors to be used. One SF_GlobalFactors Element per database is required, not per model.
The SF_GlobalFactors Element Attributes
The global factors element, SF_GlobalFactors, holds an assortment of physical properties. The standard operating conditions defined by the value of the properties can vary from company to company. The default values are the most commonly used factors in North America. (U. S. settings).
The following table lists the Attributes and their default values.
Global Factor Descriptions and Default Values
| Attribute Name | Description | Default Value |
|---|---|---|
| AirBuoyancyAdjustment | Air Buoyancy Adjustment | 0.0011 kg/L |
| BtuToFOEMass | Heating Value per mass of fuel oil | 19,720 Btu/lb |
| BtuToFOEVolume | Heating Value per volume of fuel oil | 6,050,000 Btu/bbl |
| NormalCompFactor | Normal Compressibility Factor | 1 |
| NormalGasMolarVolume | Normal Gas Molar Volume | 22.4146 Nm3/kmol |
| NormalPres | Normal Pressure | 1 atm |
| NormalTemp | Normal Temperature | 0 °C |
| ReferencePres | Reference Pressure | 14.73 psi |
| ReferenceTemp | Reference Temperature | 60 |
| StandardCompFactor | Standard Compressibility Factor | 1 |
| StandardPres | Standard Pressure | 14.73 psi |
| StandardTemp | Standard Temperature | 60 |
| StdGasMolarVolume | Standard Gas Molar Volume | 379.4932 sft3/lbmol |
| WaterDensityAtNormalTemperature | Water Density at Normal Temperature | 0.9991 kg/L |
| WaterDensityAtReferenceTemp | Water Density At Reference Temperature | 0.9990121 kg/L |
| WaterDensityAtStandardTemp | Water Density At Standard Temperature | 0.9990121 kg/L |